(1) Field of the Invention
The present invention relates to an image processing apparatus, image processing system and image processing method that outputs an image-processed result of image data received by way of a communication network from information devices such as remote PCs (personal computers) and the like, as well as to an image processing program for making a computer execute the image processing method. The present invention is particularly directed to an image processing apparatus, image processing system and image processing method capable of dealing with time-designated print requests for the image processing apparatus in its power-saving mode, as well as an image processing program for making a computer execute the image processing method.
(2) Description of the Prior Art
As an image processing apparatus that outputs the image-processed result of image data received from without, use of a so-called multi-functional peripheral (MFP) that combines several basic functions including a printer function, scanner function, facsimile function, copier function and the like and also has various functions using network communications, has been widespread. In particular, with the recent development of network communication technologies, there has been rapid evolution of image processing systems which are capable of handling various imaging processes in cooperation with image processing apparatuses including other multi-functional peripheral printers, copiers, scanners, facsimile machines and the like as well as personal computers (which will be written hereinbelow as PCs), by way of communication networks, such imaging processes including, for example, processing of transmission and reception of facsimile data, processing of network printing, processing of transfer of scanned images.
With such an image processing system, the image processing apparatus is connected to a LAN (local area network) constructed by Ethernet (registered trademark) cables etc., and receives print jobs, facsimile transmission jobs and others from remote information devices such as PCs, facsimile machines by way of this communication network. Then, the image processing apparatus subjects the image data included in these jobs to various processes so that the image processed result is output to an image forming portion.
With regards to the above image processing apparatus, in order to disperse the load on the image processing circuitry there are configurations in which sub boards can be optionally installed so as to add extra functions in addition to the main board that executes the operations of image processing. As the examples of sub boards, LAN interface boards, USB interface boards and the like are provided. In general, the main board and sub boards include a CPU (Central Processing Unit) or ASIC (Application Specific Integrated Circuit) for executing programs, flash memory for storing the programs, other memories and the like. The setting information in each image processing apparatus was previously often stored in the memory provided in the main board having a large memory capacity while sub boards were previously components for simply functioning as the interface with external devices by way of communication networks such as LAN etc.
In recent years, Energy-saving law and the International Energy Star Program and the like, demand that image processing apparatuses should be operated with low power consumption. As one of such measures toward power saving, there is a configuration of an image processing apparatus which includes a power saving mode function for suppressing the power consumption of the image processing apparatus as a whole by cutting off electric power supply to the main board while supplying power to the sub boards only when the apparatus has not been operated for a fixed period of time.
Usually, a typical image processing apparatus starts printing (image forming) when it receives a print job from an information device such as a PC or the like, via a communication network. However, there is also a proposal of an image processing apparatus which permits the information device to designate a desired printout time when the device directs the image processing apparatus to perform a print job. The image processing apparatus having the aforementioned power saving mode function has been constructed such that when it receives time-designated printing data as the image data of a print job during the power saving mode, the entire image processing apparatus inclusive of the main board is restored from the power saving mode to deal with the print job.
To deal with this, an image forming apparatus is disclosed in patent document 1 (Japanese Patent Application Laid-open No. 2002-86844), which is constructed so that, in order to suppress power consumption, when the image forming apparatus received time-designated printing data as a print job of image data in its power-saving mode, the CPU on the sub board directly accesses the memory on the main board and stores the time-designated printing data thereinto, to thereby keep up the power-saving mode as long as possible.
However, when time-designated printing data as a print job of image data is received in the power-saving mode, or when time-designated printing data received during the power-saving mode is adapted to be stored in the memory on the sub board, the memory becomes instantly full if the memory capacity of the sub board is made as small as possible. As a result, frequent recoveries from the power-saving mode occur, giving rise to a problem of inability to keep up the power saving mode. On the other hand, when large enough memory capacity is secured in the sub board, this gives rise to the cost increase problem and also the problem of increasing the power consumption during waiting. Further, when time-designated printing is performed in the image processing apparatus, it is necessary to make the apparatus active from the power-saving mode before the designated print completion time, taking into account the time required for image expansion. That is, there is the problem that the power saving mode of the apparatus is shortened by the time required for performing a process of image expansion. Further, when a multiple sets of stored time-designated printing data concentrate on a particular time, previously there occurred the problem that the designated print completion time cannot be kept exactly because each job needs time for the process of image expansion of printing data and for its printing process.